Selective TRPV2 Antagonists Derived from the Natural Product Piperlongumine Inhibit Cancer Cell Migration and Metastasis

TRPV2 is the least studied member of the vanilloid TRP
subfamily
despite its emerging relevance in cancer metastasis, pain, and inflammation.
Although several small-molecule TRPV2 modulators have been reported,
including the natural products piperlongumine (PL) and cannabidiol,
all lack selectivity, complicating the interpretation of phenotypic
readouts and functional insights into the role of the channel in health
and disease. Here, we report a series of PL-based derivatives rationally
designed to maintain TRPV2 antagonism while eliminating covalent off-target
activity associated with the electrophilic groups present in PL. Using
electrophysiological and calcium fluorescence imaging assays in HEK293T
cells and DRG nociceptors, we identified HKC54 as the most potent
TRPV2 antagonist to date (IC50 = 0.4 μM), displaying
∼50-fold selectivity over TRPV1 and ∼70-fold selectivity
over TRPA1. Cellular thermal shift assays demonstrated direct TRPV2
engagement, and molecular dynamics and docking studies suggest a near-identical
binding mode of the derivatives to PL. To assess proteome-wide selectivity,
we pursued an unbiased chemoproteomic strategy and developed photoaffinity
probes derived from PL and noncovalent derivative HKC22. Whereas the
PL-based probe labeled many established covalent and noncovalent PL
targets (e.g., GSTP1, GSTO1, STAT3, and KEAP1), no off-targets were
detected for HKC22, suggesting high selectivity for TRPV2. Finally,
PL derivatives inhibited cancer cell migration in vitro and suppressed
metastasis in vivo, underscoring the therapeutic potential of selective
TRPV2 antagonists.